HIV-infected individuals experience accelerated vascular aging and an increased risk of vascular disorders. Vascular dysfunction, similar to that underlying vascular dementia and depression seen in aging HIV-negative populations, may contribute to the continued high rates of HIV-associated neurocognitive disorders seen in the effective antiretroviral therapy era. One diagnostic marker of vasculopathy is thickening of the vessel wall. Studies have established a correlation between vessel wall thickening and vascular disease manifestations. This prospective, observational study aims to examine the relationships between neurocognitive outcomes and vessel wall thickness as a marker of vascular disease in HIV-infected adults. Study procedures include neuropsychological testing, brain imaging, blood biomarkers, magnetic resonance imaging of the carotid vessel walls and computed tomography of the heart. HIV-infected patients (n=40) and age-, sex-, and race-matched HIV-negative controls (n=40) will be recruited. Participants will be followed for two years, with clinical evaluations every 6 months and repeat imaging studies at 12 and 24 months. Cross-sectional analysis will compare markers of vascular and neurocognitive disorders between HIV-infected and HIV-negative participants. The longitudinal data analysis will assess and compare the temporal progression of vascular disease (imaging and blood biomarker findings) in relation to changes in neurocognitive and depression scores in both groups. 65 participants have enrolled to date, 40 HIV-infected adults and 25 HIV-negative controls. In the first 30 HIV-infected participants with a fully-evaluable data set, 6 (22%) have neurocognitive impairment. Carotid atherosclerosis was identified in 12 (40%). Calcified coronary artery plaque was noted in 15 (50%), with a median coronary artery calcium score of 26 (range 1-2283). Six participants (20%) have both carotid and coronary disease. Research assays and cross-sectional analysis will be completed after the planned target of 40 HIV-negative and 40 HIV-positive participants have completed baseline assessments.